Dust collector



G. C. POLK DUST COLLECTOR July 18, 1950 3 Sheets-Sheet l Fileld Sept. 16, 1947 WY B MMM

Ja., ATTQRNEY July 18, 1950 G. c. PoLK 2515594 DusT coLLEcToR Filed sept. 18, 1947 3 sneets-shee'z 2 INVEN TOR.

M ATToRNEY 5 Sheets-Sheet 3 G. C. POLK DUST COLLECTOR July 18, 1950 'Filed Sept. 16, 1947 INVENTOR. WC Fo M ATToRNEY FIG. I2

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Patented July 18, 1950 2515,?534 WST COPLCTQR Gilbert C. Polk, Detroit, Mich., assignor to Almerican Blower Corporation, `,Dearborrn lVIich., a corporation of Delaware i pplicationsentcmber 16,71347, Serial No. .774364 Thisf invention .relates to newV .and useful improvem'ents in `centrifugal separators in general I andl rorespecifically .to dust .or cinder 'col1ectors.

One. of. the' objects of this inve'rition is to providetalnewanddmroveddust collector.

'Another obietf'is to provide a'dust collector` .havingapluralityfof collector co'nduits and having arneanstolreffect a substantiall equal collectorlof-dust or"other parti'cles in each of said conduitsf nother-object isto provide va dust collector .whichisoper'ametolsenarate a gas stream into a clean lpor'tionsand .a ;partcle laden `portion vand i having an. improved means .for withdrawing the Hpartcle ladeni gasstream portion.

` vAnother,nhiect is `.to ,provide a dust collector 1having arplurality of collector .conduits of improved construction for tease' of assembly.

:In the accompanying drawingsto be taken as v ,a part; of -thisvspecificatiom there is clearly and fullyilhistratedj a preferred embodiment of this a. invention, Hinwhich drawings z ',=Figure,l is1a .view in front elevation of a dust i collector ernbpdxing this invention and having a portionfof Lt e .collector casing broken away to ssernb1y..of-the collector conduits, 2. s.a ,yiew in side elevation of Fig. 1 on a slightly-fsaiargdscale, o

-L'Figfi 1 but showing the collector conlevaton, an enlargedend View of the inlet end oflronepf' hepollector conduits similar to that hehrzokken away. portion of. Fig. 1 and zzEigz; 6 is'an, enlarged longitudinal sectional view -z'f'filler'mmber shown inffEig-z 1 .which fi11 in ;the .space betweenythe hexagonal, hads ofthe -colleotor conduitsA land the .walls w of the v collector casing.

- Referring .i to the` drawings; z by characters of reference, there is a .dust collectorv unit l1 which isoperable to separate fromair or? other gases -dust or other foreign particlea' liquid or solid. `The dust ,collector I; is operable to separate and ,collecta wide. range .of foreign `Vparticles but is especially adapted `forcollecting soot and fly ash" from thestack or flue gases of a'coallburn- -ing -furnace and the unit would probably be P.toegive a rotary motion to the partcle laden gas ;stream passing ;therethrough The rotary mo- `ltion given thegasstream passing through one of mounted between the furnace flue and an induced .draft fan discharging to the stack or chimney.

The collector unit I comprises a collector casing 2V having anrinlet header casing 3 and an outlet ``lheader casing A. The directicn of flow of the `vpartcle laden gases into and out of the collector unit I is shownb'y, the directional arrows and 6. ;Extending from theinlet headerside into the space enclosedbyjhe collector casing 2 are a ,plurality of conduits :l which arefastened to- `gether andfsupported at their inlet endsby the collector casing 2'. ``A second plurality of conduits *67 extend into the space enclosed by the collector .casing =2` frombthe outlet header side and are .similarly fastened together and supported at .their Outlet ends Vby the collector casing 2; The 20\ duits 'l and the conduits are positioned substantially. concentriicallyzwith the conduits J. Positionedinthe inlet end pf each of the conduits 1 isva-helical spinnermember H which is operable the Spinner members H is operable to throw the `foreign particles toward the Walls of the conduit l and vdivide thegas stream vinto a clean central ,portion and a partcle laden outer portion. The clean central portion of the gas stream passes out through thecqnduit 8 and the partcle laden outer portion is zdscharged through the annular spacebetween the conduit end portions 9 and In. `This separatory action is duplicated in each set ofconduits 1 and 8 and a quantitative separation thereby obtained. At the outlet en'd of each of ,the conduits-'l` is an annular cover member |2,

shown in Figs, 6 and'f, which is operable to control the discharge of the partcle laden outer portions of the plurality of'gas stream portions and is `further operable `as a supporting member 'for the conduit'end portions' 9 and' l. The cover 'member l'z comprises an annular'disc portion |3 having a pluralit'of curv'ed 'portions M which are bent into "a helical cur've; .In assembly, the lcover member |`2 isf'fitted around the conduit 8 to restrict the Outlet from the end of the conduit 1. The helically Vbent portions Id are formed to 'tightly fit into the' annular space between the conduit end portions 9 and l forming annular discharge' apertures |5 and providing arrigid support for the condinty end portions 9'and IH.v

The collector casing 2 has a bottom Wall IB comprising a horizontal portion a Vertical portion |8, and a slanting portion |9. The slanting wall portion |9 extends inward from the Outlet header side and together with the vertical wall portion |8 forms an elongated rectangular aperture 20 running transversely to the conduits 1 and 8 and located directly below the helical Outlet apertures of the cover members |2 on the conduits 1. The aperture 20 opens into a rectangular throat portion 2| of a cover member 22 to a tapered trough-shaped conduit 23. The

particle laden gas stream outer portions discharge through the helical outlet apertures |5 into the space enclosed by the collector casing 2 and are conducted downward by the wall portions |8 and |9 through the aperture 20 and throat portion 2| into the trough-shaped conduit 23. The conduit 23 is closed at one end portion 23a and has an enlarged end portion 23b forming an aperture. The conduit 23 has a sloping bottom wall and increases in cross sectional area towards the enlarged end portion 23D.

In the throat portion 2| are located a plurality of bent distributor members 24 preferably formed of sheet metal, see Figs. 8 and 9 for detail view. The distributor members 24 are positioned at varying predetermined positions (see Fig. 1) along the throat portion 2|, the distance between them increasing toward the small tapered end of the trough-shaped conduit 23. The increasing distances between the members 24 function to equalize the pressure drop across the annular members |2 so that substantially equal amounts of dust laden gas are drawn through the orifices |5 and substantially equal amounts of particles are caused to be separated by each of the conduits 1. The members 24 are positioned as to form a sloping nozzle or duct portion 24a openingV into the conduit 23 pointing toward the enlarged end portion 23h. The increasing size of fiow area of the nozzles 24a toward the closed end of the trough-shaped conduit 23 and the uniformly increasing cross section of the conduit 23 toward its outlet end cooperate to provide a uniform carrying Velocity which moves the dust particles and keeps the conduit 23 cleared of the dust or foreign particles.

The trough-shaped conduit 23 carrying the separated dust laden gas stream portions opens into a cyclone type centrifugal Separator 25 wherein the particles are separated from the secondary gas stream portion and removed through a conduit 26 at the bottom of the Separator and collected in a container 21. The cleaned gas from the Separator 25 is drawn upward through a conduit 28 by a blower 29 and discharged into the inlet header casing 3.

The inlet heads 30 of the conduits 1 and outlet heads 3| of the conduits 8 are formed in the Shape of a regular hexagon for ease of assembly. The hexagonal heads 30 and 3| are easily nested together for a rigid assembly. The heads 30 and 3| are bolted together and to the casing 2 as shown in Fig. 5. The nesting together of the hexagonal heads 30 and 3| serves the further purpose of preventing any of the gas from bypassing the conduits 'l or 8. The nested hexagonal heads 30 and 3| are operable to function as a wall member with the conduits extending therethrough. It would be possible to eliminate the heads 30 and 3| and have a solid wall with apertures for admitting the conduits but the assembly would be more difiicult and less economical for commercial construction.

Along the edges of the casing 2 where the heads 30 or 3| are bolted are positioned a plurality of filler members 32, 33 and 34 (see Figs. 10, 11 and 12) which ll in the spaces between the hexagonal heads 30 or 3| and the edges of the casing 2, see the broken away portion of Fig. 1.

The operation of this collector has been described in the process of setting forth the structure but will be restated for clarity:

Dust or other particle laden gases are conducted to the inlet header casing 3 where the gases are split into a plurality of gas stream portions'and enter the conduits As the gases enter the conduits 1 they pass through the Spinner members and are given a high rotary motion thereby. The high rotary motion of the gases in the conduits is operable to throw the particles towards the walls of the conduits and to divide the gases into a clean central portion and a particle laden outer portion. The clean central portions pass through the conduits 8 into the outlet header 4 and are discharged therefrom as indicated by the directional arrow 6. The gas stream particle laden outer portions are discharged through the helical apertures |5 into the space enclosed by the collector casing 2. The particle laden gas stream portions are then conducted downward through the aperture 20 and throat portion 2| to the trough-shaped conduit 23 which leads to the "cyclone collector 25. If there were no obstruction or distributor members in the throat portion 2| there would be a greater pressure drop through outlet members |2 of the conduits adjacent the outlet end of the troughshaped conduit 23, and an unequal and inelficient separation would be had through the other conduits. The distributor members 24 are operable to eliminate this undesirable feature by equalizing the pressure drop across the various conduit outlet members |2. The members 24 are closest together at the end of the throat portion 2| adjacent the outlet end of the trough-shaped conduit 23 where the pressure drop across the conduits 1 would normally be the highest and gradually increase in spacing toward the small tapered end of the conduit 23. This variable and increasing spacing between the members 24 is operable to cause equal amounts of particle laden gases to be drawn therebetween thereby to equalize the amounts of particle laden gases passing through the conduits 'l and the pressure drops thereacross. The particle laden gas stream portions discharging from the trough-shaped conduit 23 into the cyclone type Separator 25 are further separated therein and the particles collected in a container 21. The gases from the Separator 25 are drawn upward through a conduit 28 by a blower 29 which discharges them into the inlet header casing 3 to be recirculated with the incoming particle laden gases.

What is claimed and is desired to be secured by Letters Patent of the United States is:

1. A dust collector comprising a plurality of conduits each operable to ,receive a gas stream laden with foreign particles, means for imparting a rotary motion to each of said particle laden gas streams thereby to throw said foreign particles toward the walls of said conduits and to divide said gas streams into clean central portions and particle laden outer portions, a second plurality of conduits of smaller size positioned substantially concentrically in the outlet ends of said first-named conduits and operable to receive said gas stream central portions, said gas stream particle laden outer portions discharging through izftamasazr r'rthef annularhspaces betweemsai'd firstgnamedland asaid .second I l conduits, means: wenclosing a'space :faround said second cOnduitsHandmeansto effect -azwithdrawal of said idischarging particlei'laden i 'gasstream portionsfrom saidzlast-namedspace so that;` the pressure drop. through each'ofi: saidsannular spaces Will be substantiallysequal saidflastnamed means con'mrisinga .plu-rality zof idischarge apertures each opening into saidaspace-andsuccessively increasing' in'ifiow area.: across: said col- `-1ector 'tr'ansverselyto said conduits.

1* 2. VA dust collector comprising Vafplurality' of .nularspaces between said first-named and-l said' 1 second conduitsfmeans enclosinga space-around .;isaid'second:conduits,-means to conductsaid particle laden gaslstream portions from-'said'lastnamed 'space and away from the -outletfends of said=first'-named conduits, and means=-to `distributeuniformly theentrance -of said--particle laden-'gas' stream portions into said-'conducting means sol that' a`V substantially i equal' collection of particles may be had from each of-said`frstnamed conduits, said last-named' meanscornpris- 1' ing a plurali'tyof'discharge apertures each-opening from said fspacefinto said conducting means and succes'sivelyincreasing in '-fiow- ``Aalong H said conducting means.

f 3. A dust collector ecomprising-a casing, a

'lpluralityiof conduits extending into said1casing and veach'operable'to receive a gasf'stream'laden with foreign partic1es,--.means' for' impart'ing a 'rotary motion' to each of said '-'particle `'laden gas streams therebytothrow said 'foreignpar- 45 ticles toward the'walls of said conduits and to dividesaid gas'streams into clean centralporvtions and particle laden outer portions, a-second pluralityof conduits of'smaller'size positioned -substantia1lyconcentrically in the outlet ends of said first-named conduits and 'operable to `receive said'gas 44stream vcentralportionssaid 'casing enclosing the space aroundsaid-*firstnamedand said second conduits, said; gas stream -outer portions discharging through the annular space between saidfirSt-named and said second conduits into the .space enclosed by said casing, said casing having a bottom Wall with an opening therethrou'gh extending* transversely' to said conduits, a trough-shaped conduit member covering said-opening and' operalcole'toy conduct away said gas stream outer portions, and dividingmem- .bersspaced at predetermined and successively i increasing intervals along saidopeningfand opterable to, control "the`'distrib\ltion ,of-1 saidgas stream outer portions entering sa id ,tro,ugh-

shaped conduit thereby to effect a substantially 56 'lzportionvandi af, particle -ladonzouter znamion, a :fsecond'zconduit 4ofzsmallenSizepositioned substanfo:tiallyconcentricallyfin.theoutlet end of said ;firstmamedeconduit;anduoperable to receive said gas 5 sstream.centrallportion; lsaid first-named; conduit :fbeing-fsupported; at' :its inlet end .and said second :oonduitbei-ng :supported` at A its f-outlet Aend,z and an` .annular idisc `member :closing the outletg end ofl ;said first-;named` conduit,V said disc member :zhavting av :plura'lity :of lfprojecting portions and `zapertures;.therethrough,=1said .disc member por- =-tio ns` fbeingetightly: fitted ;in :the annular space 's-;between:saidffirstenamed ;andV said second -con- -duits,';said-.;apertures providing for the discharge 1 i :of'z said; gas; stream: ;outer portiom land said -:disc :fmember portionsengaging ;the'walls of the Outlet sendzportion-ofzsaidifirst-named conduit and-:nlet ffzendgportion of 'saidrsecond conduit'ltoprovide a lrigidzsupporting.vmeanszitlaorefor and to hold said :idisc lmember ;inl position.

' EMA` :dust fcol'lectori.` comprsns a casing, a z;,atllurality`` of :conduits extendinginto-zsaid', casing nand each `operablejgto receive:l a gas: stream' ;laden with- 4foreign::particles means for imparting a rotary motionitoeachof'. said particle laden gas `-eams'thereby' to throwzsaidil foreign `particles a owlardjthe:wa11s; ofz,said conduits and to divide fiisaidagas'rstreams :into :clean central portions and rparticlexzladen outer-,portions a'V second` plurality goizofnconduits fof: smallersize-` positionedr substan- ;frtially concentricall'ydin;the outlet ends ;of said ;-.=.:first,-.named= conduitsiand operable to| receive said .gas streamR centr.al.portions,l said first-named conf duits fibeing supported ;by said;` casing ;atptheir inlet ends and said second ;conduits :being-sup- H.portecLfby'` saidticasing ;atiheir out-let ends, a naplurali'tyzlof: anmllar disc :members closing the 2 :outletzend l`ot `YVeach of ;saidfirst-named; conduits, .fsaidzzdisczzmembers each Ehaving a--plu rality of .wfzsupporting lportionsxand, openings; said :disc memberfsupporting portions 'being ;tightlyafitted in 'zthef-annular space between said firstL- named and i '-.saich second ;conduits and, engagingthe respective wallsthereof; saidzhopenings forming a; plurality of iamertures:forthe ldischargeof said i gas-V stream :outer '1 portion, Vsaid ;supporting portions rigidly :sup-porting the ;Outlet ends 'of saidfirst-named fgconduits: and-` inlet, endsr of ;said `second-named wconduitsand, holding said disc members -rigidly ::in' 'postiornsaid 'gasstream outer portionsdis- 'charging ;through saidv apertures into :the space 'Lenclosed'bysaid 'casing, saidfcasnglhaving a mbottom :wall Withan opening `therethrough, a

:trougl'r-shaped i conduit i member covering said opening? and operableto conducteaway'said gas stream outer o portions, w and dividing members `'{;spacedzl;atzpredetermined intervals along said AP:openingand operable to control the distribution ci-said gasustreamaouter: portions entering` said trou'gh-fshaped conduit :thereby to effectl a subi 'zstantially equal'c'ollection of particles from 'each :vor-:sami first-namedx conduits and' a substantially *equal" pressure .drop 1across-ea`chfof. said aper- `'1"tures.

6:- A dust c'ollector'comprisinga casing, a' plu- -ral-ity of conduits extending into-said casing and `each operable to receive'a'gas'stream'laden with foreign particles, means for imparting a rotary motion to each of said particle laden gas streams To thereby to throw said foreign particles toward the Walls of said conduits and to divide said gas streams into clean central portions and particle laden outer portions, a second plurality of conduits of smaller size positioned substantially 'concentrica11y in the Outlet ends of said firstnamed conduits and-operable to. receive said gas stream central portions, the inlet ends 'of said rst-named conduits and the Outlet ends Of said secondconduits having hexagonally shaped head portions which are operable to be nested together in a tightly fitting position thereby preventing bypassing of gas around said conduits, said' hexagonal head portions being supported by said casing, a plurality of annular disc members closing the Outlet end of each of said first-named conduits, said disc members each having a plurality of cut portions bent in the form of a helix, said disc member helical portions being tightly fitted in the annular space between said first-named and said second conduits and forming a plurality of helical apertures for the discharge of said gas stream outer portion, said disc members and helical portions thereof forming rigid supporting members for the Outlet ends of said first-named conduits and inlet ends of said second-named conduits, said gas stream outer portions discharging through said helical apertures into the space enclosed by said casing, said casing having a bottom wall with an opening therethrough, a troughshaped conduit member covering said opening and operable to conduct away said gas stream outer portions, and inverted curved dividing members spaced at predetermined intervals along said opening and operable to control the distribution of said gas stream outer portions entering said trough-shaped conduit thereby to effect a substantially equal collection of particles from each of said first-named conduits and a substantially equal pressure drop arcoss each of said disc members.

7. A dust collector comprising a casing, a plurality of conduits extending into said casing and each operable to receive a gas stream laden with foreign particles, means to cause said gas streams to rotate thereby to throw said particles toward the walls of said conduits and divide said gas streams into clean central portions and particle laden outer portions, a second plurality of conduits positioned substantially concentrically in the outlet end portions of said first-named conuits and operable to receive said gas stream central portions, the inlet ends of said first-named conduits and the Outlet ends of said second conduits having head portions of hexagonal shape operable to be nested tightly together to prevent bypassing of said gas streams around any of said conduits, said hexagonal head portions being supported by said casing which encloses the space around all of said conduits, said gas stream outer portions discharging into the space enclosed by said casing, said casing having a bottom wall which has a slanting portion and a Vertical portion terminating in an opening running transverse to said conduits and positioned below the Outlet ends of said first-named conduits, said slanting wall portion extending from the edge of said casing adjacent the Outlet ends of said second conduits thereby to direct said gas stream outer portions toward said casing wall opening, said casing wall opening being alined with and opening into a throat portion of a tapered trOugh-shaped conduit, said trough-shaped conduit being operableitovconduct away said particle iaden gas stream outer. portions, andl inverted curved dividing members spaced at predetermined intervals in said conduit throat portion and operable to control the distribution of said gas stream outer portions entering said troughshaped conduit thereby to effect a substantially equal collection of particles from each of said first-named conduits.

8. In a Separator for removing foreign particles from a gas stream, a casing having a Vertical wall, a plurality of horizontally disposed conduits in said casing and having their inlet ends opening through said wall, means to separate foreign particles from gas streams supplied to said conduits, said casing having a bottom wall opening extending transverse to said conduits for discharge of the foreign particles from said casing, a trough closing said bottom wall Opening and having an Outlet, and means subdividing said bottom wall opening into a plurality of spaced ports, said ports being of successively increasing flow area away from said trough Outlet.

9. In a Separator for removing foreign particles from a gas stream, a casing having a Vertical wall, a plurality of horizontally disposed conduits in said casing and having their inlet ends opening through said wall, means to separate foreign particles from gas streams supplied to said conduits, said casing having a bottom wall opening extending transverse to said conduits for discharge of the foreign particles from said casing, a trough closing said bottom Wall opening and having an Outlet, and means subdividing said bottom wall opening into a plurality of spaced ducts, said ducts being of successively increasing flow area away from said trough Outlet, said ducts being directed toward said trough Outlet.

10. Flow equalizing means comprising a horizontal trough having an end Outlet and with an inclined bottom wall sloping downward to said Outlet, said trough having a top Wall opening extending longitudinally thereof, means separating said opening into a plurality of spaced ports, said ports being of successively increasing fiow area away from said trough Outlet.

11. Flow equalizing means comprising a horizontal trough having an end Outlet and with an inclined bottom wall sloping downward to said Outlet, said trough having a top wall opening extending longitudinally thereof, means subdividing said wall opening into a plurality of spaced ducts, said ducts being of successively increasing fiow area away from said trough Outlet, and said ducts being directed toward said trough Outlet.

GILBERT C. POLK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 893,968 Allington July 21, 1908 1,717,639 Waters June 18, 1929 1,846,719 Gross Feb. 23, 1932 2,188,206 Pfeifer et al. Jan. 23, 1940 

